Corner rounding punch and die assembly



June 23; 1970 N. E. SUNDQUIST ET AL 3,516,317

CORNER ROUNDING PUNCH AND DIE ASSEMBLY Filed May 51. 1968 2 Sheets-Sheet1 FIG: 5'

' INVENTOR Fl 5'. 7

lV/LS E. SUN-D 00/5 7' Gill/7041f. P4775850 BMJQK 3M L J /8 54 I June23, 1970 E, su nqu s ET AL 3,516,317

CORNER ROUNDING PUNCH AND DIE ASSEMBLY Filed May 31, 1968 2 Sheets-Sheet2 JET a.

i glllilllll .umm 11ml Il l 7 4 49 l 27 l W 4 I8 50 53 HHW' II I f //|lil l i M I U l I N VEN TORS FIG 4 AIMS z. smvmpu/sr 4 rroRn/Eys UnitedStates Patent 3,516,317 CORNER ROUNDING PUNCH AND DIE ASSEMBLY Nils E.Sundquist and Clinton E. Patterson, Minneapolis,

Minn., assignol's to Mate Punch and Die Co., Minneapolis, Minn., acorporation of Minnesota Filed May 31, 1968, Ser. No. 733,686

Int. Cl. B26d 7/16, 3/10 U.S. Cl. 83-467 14 Claims ABSTRACT OF THEDISCLOSURE A punch and die assembly for rounding the corners of a sheetmetal work piece. The assembly has a plurality of cutting positions sothat the corners of a work piece be cut to different size radii throughthe use of a single punch and die. The die has a plurality of alignedarcuate cutting projections of different size radii. The punch hascomplementary recesses which cooperate with the die projections onmovement of the punch toward the die to effect a shearing operation. Aguide bar adjusta'bly mounted in selective positions on the die alignsthe corner of the work piece with a selected projection so that thecorner of the work piece is rounded on movement of the punch toward thedie.

SUMMARY OF INVENTION The invention relates to a multiple corner punchand die assembly usable to provide a number of different size radii forthe corners of a work piece with a minimum of set up time and Withoutmeasurement or adjustment. The

punch and die assembly has a die with a plurality of cuttingprojections. Each cutting projection is arcuate with a different sizedradius. Cooperating with the projections is a movable die having aplurality of arcuate recesses which correspond to the die projections. Agauge bar is selectively mounted on the die in a number of positions toalign the corner of the work piece with one of the cutting projectionsand the cooperating punch recess so that a selected radius is cut on thecorner of the work pieceon movement of the punch toward the die.

In the drawings:

FIG. 1 is a fragmentary side view of a punch press set up with thecorner punch and die assembly of the invention;

FIG. 2 is an enlarged sectional view taken along the line 22 of FIG. 1partly broken away to show the punch, the die, and the gauge bar;

FIG. 3 is a front elevational view of the punch and die assembly;

FIG. 4 is a rear elevational view of the punch and die assembly;

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 2;

FIG. 6 is a view similar to FIG. 5 showing the cutting of the workpiece; and

FIG. 7 is a sectional view taken along the line 77 of FIG. 3 with thegauge bar removed.

Referring to the drawings there is shown in FIG. 1, a conventional punchpress indicated generally at 10 set up with the punch and die assemblyof the invention indicated generally at 11. Punch press 10 has ahorizontal bottom table 12 located below a power driven movable member13. On operation of the press 11) the movable member 13 ice issqeuentially driven toward and away from the table 12 to effect theoperation of the punch and die assembly 11.

Punch and die assembly 11 has a base 14 secured to the table 12 and amovable head 16 engaging the bottom of the movable member 13. A die 17is secured to the base and a punch 18 is attached to the head 16. Onoperation of the press 10 the punch 18 moves downwardly relative to thedie 17 to cut the work piece with shearing forces. The punch and dieassembly has a plurality of work positions which are selectively used toprovide the corners of sheet work pieces with different size radii. Theassembly can be converted to change the radius of the corner of the workpiece with a minimum of set up time without measurement or adjustment ofany part of the assembly.

Referring to FIGS. 4 and 7, base 14 is a rectangularshaped metal blockhaving a downwardly inclined cutout 19 along one side providing a chutefor the waste material, slugs and chips cut from the work piece.Opposite ends of the base 14 have holes 20 for accommodating bolts usedto secure the punch and die assembly 11 to the table 12. Projectedupwardly from opposite end sections of the base are upright posts 21 and22 for movably supporting and aligning the head and die on the base. Theupper ends of posts 21 and 22 slidably project through bearings 23 and24 and into bores 26 and 27 respectively, in the head 16. Positionedabout the posts 21 and 22 between the bearings and base 14 are coiledsprings 28 and 29 respectively which bias the head and die upwardlyholding the punch and die assembly in an open position.

As shown in FIG. 4, the die 18 is secured to the bottom of head 16 abovethe die 17 with a plurality of upright bolts 31. A stop assemblyindicated generally at 32 secured to the die 18 functions to limit theupward movement or open position of the die. The details of stop 32,shown in FIG. 5, comprise an upright cylindrical shank 33 having athread upper end 34 threaded into the mid-section of the die 18. Thelower end of shank 33 projects through an upright hole 35 in the base14. A bolt 36 is threaded into the lower end of shank 33 providing astop which can adjust the open position of the die. The head of bolt 36is located in a recess 37 extended upwardly from the bottom of base 14.As shown in FIG. 6, when the die 18 is in the lowered cut position theshank 33 slides through the hole 35 lowering the bolt 36 in the recess37.

Refening to FIGS. 2 and 7, the die 17 located on base 14 has a flathoriznotal upper surface or platform 38 forming a horizontal support forthe work piece 68. Opposite end sections of the dies have upright holesfor accommodating bolts 39 used to secure the die to the base 14. Theforward side of the die 17 has a plurality of linearly spaced arcuateprojections 41, 42, 43, 44, and 46. Each projection has a differentradius making the projections of unequal size. The centers of each ofthe radii of the projections lie along lines that transversely bisecteach of the projections.

Punch 18 has an outwardly directed side formed with a plurality oflinear spaced upright recesses 47, 48, 49, 5t), 51 and 52 which arecomplementary in shape to the projections 41-46 whereby the opposingedges of the projections and recesses form coacting cutting edgesoperable to shear the corner of the work piece.

As shown in FIGS. 3, 5, and 6, each recess opens to an upwardly directedtransverse groove 54 in the bottom of the punch 18 extended rearwardlyfrom the punch cutting edge 56. The portions of the punch 18 between thegrooves form downwardly projected teeth or heels 57 which extend belowthe cutting edge 60 of the die 17 when the die is in the open position.This prevents movement of the work piece under the die. The teeth act asstops as well as positioners to locate the corner of the work piece inproper cutting position between the cutting edges of the die and punch.The opposite sides of each recess has chamfered edges 58 which lie alongthe planes which are normally disposed with respect to each other sothat each chamfered edge is positioned approximately 45 from thetransverse center line of the recess. The chamfered edges 58 providefiat surfaces which are tangent to the radii of the recess so that thecorner of the work piece can be properly aligned with the cutting edgesof the die and punch.

Selectively positioned on the platform 38 is a work positioning gaugebar or line up bar indicated generally at 59. Bar. 59 is in the shape ofa flat parallelogram having straight guide edges 61 and 62. The innerend of bar 59 has a vertical pin 63 which extends above and below thebar. Projected downwardly into die 17 are a plurality of longitudinallyspaced holes 64 for receiving the downwardly projected portion of thepin 63 to position the guage bar 54 on the die 17. The outer end of bar59 has a hole for accommodating a bolt 66 turned into one of a pluralityof longitudinally spaced threaded bores 67 extended downwardly into die17. The opposite acute angles of the gauge bar are 45 degrees. When thepin 63 is in one of the holes 64 and bolt 66 is threaded in acoordinated hole 67, one of the side edges 61 or 62 of the bar isaligned with one chamfered edge of one recess of the punch 18. As shownin FIG. 2, the bar 59 is reversible so that all of the cooperating dieprojections and punch recesses may be used to form corners in the workpiece 68. The holes 63 and threaded bores 67 are aligned in pairs withrespect to each other whereby the gauge bar 59 may be placed on the dieplatform 38 in a plurality of left hand and right hand positions so thatall of the cooperating projections and recesses may be utilized to formdifferent size rounded corners on the work piece.

In operation, the work piece 68 is placed flat on the platform 38 withthe corner portion extended into the groove 54 between heels 57. Oneedge of the work piece is placed against the side of the gauge bar 59.As shown in FIG. 2, the work piece 68 is placed against the side edge 61with the corner of the work piece extended into the recess 48 above theprojection 42 and the die cutting edge 60. The gauge bar 59 aligns thecorner in the recess so that the radius of the recess bisects the cornerof the work piece so that a symmetrical round is cut on the work piece.On operation of the press the movable member 13 forces the head 16 downmoving the punch 18 toward the base 14. The cutting edge 56 of the punchshears the corner of the work piece. The slug 69 falls under the punchinto the chute 19 as shown in FIG. 6. The head 18 moves downwardlyagainst the biasing forces of springs 28 and 29. On release of the forceon the member 13, springs 28 and 29 bias the head and punch 18 back tothe open position as shown in FIG. 5. This places the punch and dieassembly in a position to effect a second shearing operation.

Referring to FIG. 7, the punch and die assembly is usable to roundcorners of a work piece without the use of the gauge bar 59. The workpiece is placed flat on the platform with the corner in punch recess 49over die projection 43. The fiat side surfaces of the chamfered edges58, shown in FIG. 3, align the work piece between the punch and diecutting edges so that the corner is cut round.

While there have been shown and described a punch and die assembly withsix cooperating corner projections and recess it is obvious to oneskilled in the art that any number of cooperating projections andrecesses can be provided in the die and punch and the gauge bar 59 canbe placed in numerous positions to provide a guide for the work piece.Other changes and modifications can be made by those skilled in the artwithout departing from the spirit of the invention. The invention isdefined in the following claims.

The embodiments of the invention in which an exclusive property isclaimed are defined as follows:

1. A punch and die assembly comprising: a die having a plurality ofspaced arcuate cutting edges, a punch having a plurality of spacedarcuate cutting edges which c0- incide in shape with the cutting edgesof the die, means mounting the punch and die for relative movementtoward and away from each other and locating the coinciding die andpunch cutting edges in close cutting alignment, guide means selectivelyattached to the die in one of a number of positions for aligning acorner of a work piece between one cutting edge of the die and thecorresponding one cutting edge of the punch whereby on relative movementof the punch and die the corner of the work piece is severed from thework piece.

2. The assembly of claim 1 wherein the die has a plurality of spacedprojections, each projection having an arcuate cutting edge, said punchhaving a plurality of recesses, each recess forming a cutting edgecorresponding to the coinciding cutting edge of the projection.

3. The assembly of claim 2 wherein each cutting edge of the projectionshas a different radius.

4. The assembly of claim 2 wherein the guide means comprise a bar havingat least one linear edge and means releasably securing the bar to thedie to align the linear edge with one side of a recess whereby a cornerof the work piece is positioned between the punch cutting edge and thecorresponding die cutting edge.

5. The assembly of claim 4 wherein the releasable means comprises a pinat one end of the bar projected into a hole in the die and a boltthreaded into the die at the other end of the bar.

6. The assembly of claim 4 wherein the bar is a flat parallelogrammember having linear side edges selectively usable to align the workpiece on the die with a corner of the work piece located between thepunch edge and the corresponding die cutting edge.

7. The assembly of claim 2 wherein said punch has teeth located betweenthe arcuate cutting edges of the punch, said teeth have bottom edgesprojected below the plane of the cutting edges of the die.

8. The assembly of claim 7 including a base, means securing the die tothe base, a head, means connecting the punch to the head, a springbiasing the head away from the base, and stop means limiting movement ofthe punch from the die.

9. The assembly of claim 8 wherein said stop means is adjustable tochange the open position of the punch relative to the die.

10. The assembly of claim 1 wherein the arcuate die cutting edges arespaced along one side of the die and the coinciding punch cutting edgesare spaced along one side of the punch facing the die.

11. The assembly of claim 1 wherein the punch has a plurality of spacedrecesses, outwardly projected teeth on each side of each recess, saidspaced arcuate cutting edges of the punch located between adjacentteeth, said teeth having side guide surfaces generally tangent to theradii of the arcuate cutting edges of the punch associated with adjacentteeth.

12. A punch and die assembly comprising: a die having a plurality ofspaced projections along one side of the die, each projection having anarcuate cutting edge, a punch having a plurality of spaced recesses,outwardly projected teeth on each side of each recess, and arcuatecutting edges located between adjacent teeth coinciding in shape to thecutting edges of the die, said teeth having guide surfaces tangent tothe radii of the arcuate cutting edges of the punch associated withadjacent teeth to locate the work piece between the cooperating cuttingedges of the die and punch, and means mounting the punch and die forrelative movement toward and 5 6 away from each other and locating thecoinciding die References Cited and punch cutting edges in close cuttingalignment. UNITED STATES PATENTS 13. The assembly of claim 12 whereinthe cutting edges of the die have different radius and the cutting edges2656'888 10/1953 q 83 620 X of the punch have radii which correspond todifferent 312592O 3/1964 Smlth 83 9l7 X 5 3,357,289 12/1967 Thomson83-62Q X radii of the cutting edges of the die.

14. The assembly of claim 12 including a guide means selectively mountedon the die in a number of positions WILLIAM LAWSON Pnmary Exammer foraligning a corner of a work piece between one cut- U S Cl X R ting edgeof the die and the corresponding cutting edge 10 of the punch said guidemeans have an edge aligned with one guide surface on one of the teeth.

